Numerical Reliability Study Based on Rheological Input for Bingham Paste Pumping Using a Finite Volume Approach in OpenFOAM

Abstract

Rheological quantification is important in many industries, the concrete industry in particular, e.g., pumping, form filling, etc. Instead of performing expensive and time-consuming experiments, numerical simulations are a powerful means in view of rheological assessment. However, due to the unclear numerical reliability and the uncertainty of rheological input data, it is important for the construction industry to assess the numerical outcome. To reduce the numerical domain of cementitious suspensions, we assessed the numerical finite volume simulations of Bingham paste pumping flows in OpenFOAM. We analysed the numerical reliability, first, irrespective of its rheological input by comparison with the literature and theory, and second, dependent on a certain rheological quantification by comparison with pumping experiments. Irrespective of the rheological input, the numerical results were significantly accurate. Dependent on the rheological input, a numerical mismatch, however, existed. Errors below 1% can be expected for proposed numerical rules of thumb: a bi-viscous regularisation, with pressure numbers higher than 5/4. To improve bias due to uncertain rheology, a rheological configuration close to the engineer’s aimed application should be used. However, important phenomena should not be overlooked. Further assessment for lubrication flows, in, e.g., concrete pumping, is still necessary to address concerns of reliability and stability.

Research on rheological behavior of fresh concrete single-cylinder pumping based on SPH-DEM

“…The classical computational fluid dynamics (CFD) approach treats concrete as a single fluid phase, ignoring the coarse aggregates, reinforcing fibers and other large scale particles in it, and calculates the concrete mesh flux to obtain the velocity variation and shear deformation region of the concrete flow process 16 . Robin De Schryver et al 17 used OpenFOAM (OpenFOAM Fundation Ltd, incorporated in England) single-phase flow to calculate the pressure of the concrete pumping process, the results are one pressure value higher than the experimental values, which is explained by the fact that concrete undergoes compositional changes during transport in the pumping pipeline, which results in much smaller rheological parameters near the walls than the actual concrete.Secrieru et al 18 and others, using the commercial software Fluent (Ansys Ltd), divided the concrete into two phases, using the rheological parameters of the lubrication layer near the wall and the internal plunger flow using the rheological parameters of the concrete itself for pumping pressure analysis, and the simulation results were very close to the experimental numerical results.…”

Computational Analysis of Concrete Flow in a Reinforced Bored Pile Using the Porous Medium Approach

“…In particular, analysis of the model parameters, i.e., a sensitivity analysis would provide insight into the mechanisms and factors that govern the quality of the reinforced concrete and allow assessing the need or requirements for changes in structural or also concrete mix design. Fresh concrete can be numerically simulated using Lagrangian models [5][6][7][8] or Eulerian models [9][10][11]. See [12] for an overview of the two approaches.…”

Research on Rheological Behavior of Fresh Concrete Single-cylinder Pumping Based on SPH-DEM

“…Subsequent studies have improved the linear relationship of the Bingham model, making the model retain the original yield stress with the addition of a nonlinear fit 15 , i.e., 𝜏 = 𝜏 𝑦 + 𝐾(𝛾)𝛾̇𝑛, which adds a power-law index 𝑛 that allows the model to characterize shear thinning or shear thickening phenomena. The classical computational fluid dynamics (CFD) approach treats concrete as a single fluid phase, ignoring the coarse aggregates, reinforcing fibers and other large scale particles in it, and calculates the concrete mesh flux to obtain the velocity variation and shear deformation region of the concrete flow process 16 .Robin De Schryver et al 17 used OpenFOAM (OpenFOAM Fundation Ltd, incorporated in England) single-phase flow to calculate the pressure of the concrete pumping process, the results are one pressure value higher than the experimental values, which is explained by the fact that concrete undergoes compositional changes during transport in the pumping pipeline, which results in much smaller rheological parameters near the walls than the actual concrete.Secrieru et al 18 and others, using the commercial software Fluent (Ansys Ltd), divided the concrete into two phases, using the rheological parameters of the lubrication layer near the wall and the internal plunger flow using the rheological parameters of the concrete itself for pumping pressure analysis, and the simulation results were very close to the experimental numerical results.…”